1. Field of the Invention
This invention is generally concerned with converting solute/solvent compositions into solute-based products through use of desiccation and/or evaporation chambers. More specifically, this invention is concerned with converting solute/solvent compositions to dried solute-based products that are created by injecting atomized portions of such solute/solvent compositions into desiccation/evaporation chambers through which a heated gas stream (e.g., a heated air stream) passes. In effect, the heated gas stream entrains the atomized solute/solvent droplets, heats them and drives off their liquid components to produce a substantially dry, solid form of the solute(s) of the original solute/solvent composition.
These desiccation/evaporation operations have also been carried out in desiccation/evaporation chambers that further comprise a fluid-bed. In such systems, the atomized solute/solvent droplets are sprayed onto the individual, gas stream suspended, particles that make up the fluid-bed. In effect, the sprayed solute/solvent composition coats the gas stream suspended, fluid-bed particles. This coating solidifies on the individual fluid-bed particles as the solvent component of the solute/solvent composition is driven from the surfaces of the individual fluid-bed particles by the heated gas stream. Again, such heated gas streams will normally be heated air.
By way of a more specific example of this art, U.S. Pat. No. 6,296,790 teaches producing magnesium chloride granules by preparing a MgCl2 solution that is, at high temperatures, atomized into a fluid-bed of dried “seeding” particles. In effect, the atomized MgCl2 feed solution coats the seeds with a layer of MgCl2 solution. Meanwhile, a pre-heated air stream is forced upwardly through the fluid-bed to drive off the water component of the MgCl2 feed solution and thereby create dried MgCl2 particles which are the “end product” of this process.
U.S. Pat. No. 6,413,749 teaches production of granules that are ultimately comprised of an admixture of protein and starch that are layered over inert particles (e.g., inert particles comprising inorganic salts, sugars, small organic molecules, clays, etc.). This “layering” of the inert particles with the protein/starch admixture can be accomplished by, among various methods, fluid-bed coating the inert particles with solutions of the protein/starch admixture solution. The end product (i.e., protein and starch coated inert particles) is created when a liquid carrier component of the liquid admixture of protein and starch is driven off through use of a heated air stream.
U.S. Pat. No. 6,767,882 teaches a process for preparing detergent particles having a coating layer of water-soluble inorganic material. The detergent particle comprises a particle core of a detergent active material. This particle core is then at least partially covered by a particle coating layer of a water soluble inorganic material. Particularly preferred inorganic materials are non-hydrate inorganic coating materials such as double salt combinations of alkali metal carbonates, and sulfates. The process includes the steps of passing the core particles through a low speed fluid-bed mixer and thereby coating said core particles with a coating solution or slurry of the water soluble inorganic material.
U.S. Pat. No. 6,189,234 discloses a continuous flow, fluid-bed dryer having a dryer housing which further comprises a drying chamber and a plenum chamber located beneath the drying chamber. Moist product to be dried is introduced into the drying chamber at a product inlet and then proceeds through the drying chamber to a discharge housing. A porous screen partially separates the drying chamber and the plenum chamber. Heated air is introduced into the plenum chamber which then passes through the screen to the drying chamber to dry the product material in the drying chamber. A shaft extends centrally through the drying chamber and is mounted for slow rotation therein. A plurality of paddles are connected to that shaft. The paddles move about a path of rotation such that the paddle ends sequentially sweep over the surface of the screen. In doing so, the paddles momentarily move product away from the screen and thereby permitting a rush of heated air to enter into the drying chamber in order to locally fluidize the particle bed and further drying the product material.
U.S. Pat. No. 5,254,168 teaches a fluid-bed particle coater having a dual-jet and spray arrangement. It includes an upstanding column which has an upper cylindrical section, a tapered intermediate section and a lower cylindrical section. A cylindrical chamber depends from the lower cylindrical section which is connected to tubular sections adapted to introduce multiple air streams via separately controlled inlet openings. The dual-jet and spray construction includes an upwardly-facing spray nozzle positioned in coaxial relationship to the tubular sections. A fountain tube is disposed above a draft tube. The fountain and draft tube concentrically intersect about an intermediate section of the column in an opened telescopic arrangement. The dual-jet and spray particle coater thereby provides multiple coating and drying zones.
2. Discussion of the Background
Peroxysolvate of potassium fluoride compounds i.e., KF.nH2O2 compounds e.g., potassium fluoride hydroperoxide (KF.H2O2), potassium fluoride dihydroxide (KF.2H2O2) and potassium fluoride trihydroperoxide (KF.3H2O2) have been produced through the use of various heat/cold driven production processes that produce a solute product from a solute/solvent composition. For example, the water components of aqueous solutions of certain solute starting materials (e.g., KF, KHF2, H2O2) have been frozen through use of liquid nitrogen (especially under vacuum conditions) in order to create KF.nH2O2 end product compounds. In effect, the solute components of these aqueous solutions (e.g., KF, KHF2, H2O2) are concentrated and eventually reacted to form the desired KF.nH2O2 compounds as more and more ice (which is comprised of virtually pure water) is formed from the solvent (water) component of the solute (KF, KHF2, H2O2)/solvent (H2O) solutions undergoing the liquid nitrogen driven, water freezing operation. Owing to their use of liquid nitrogen as a means of producing freezing conditions, these processes are complex, cumbersome and expensive, especially in large scale operations.
Russian Patent RU 2043775 entitled “Device for Preparation of a Decontaminant and Disinfectant Potassium Fluoride Peroxyhydrate” teaches a method for manufacturing KF.nH2O2 compounds wherein a working solution comprised of water, potassium fluoride dehydrate (KF.2H2O) and hydrogen peroxide (H2O2) is created in a mixing tank where these compounds are reacted to create a liquid KF.nH2O2 composition. After filtering, this composition is fed into a pressure tank, and then into an evaporator unit where the composition's water component is evaporated under vacuum conditions. The resulting dried KF.nH2O2 product is then transferred to another container that is equipped with an airlock device in order to obtain the dried product without losing the system's temperature and vacuum conditions. This production system is complex and therefore expensive to build and operate—especially owing to its use of vacuum conditions to carry out its evaporation process).
Russian Patent SU 1467932 A1 also teaches creation of KF.nH2O2 products through use of vacuum conditions in its reaction chamber.
Russian journal: Zh. Neorg. Khim: vol 32, pages 26 12-15 (1987) contains an article entitled “Potassium Fluoride Peroxyhydrates KF.H2O2, KF.2H2O and KF.3H2O.” It also teaches use of vacuum conditions in evaporation chambers to produce KF.nH2O2 products.
Other Russian workers have prepared peroxysolvate of potassium fluoride compounds using potassium fluoride dihydrate (KF.2H2O) as catalysts in production systems wherein aqueous KHF2, H2O2, and KF.2H2O feed solutions were fed into heated air streams in order to drive off the water component of these feed solutions. These production systems also employed vacuum conditions in their evaporation chamber. None of these systems, however, employed fluid-bed systems as a part of their modus operandi. In any case, these prior art production systems produced KF.H2O2 end product yields of about 22%. These product yield results are to be compared to those of applicant's methods—which produce KF.H2O2 end product yields of about 50%.